Novel rearrangement and cyclization processes resulting from bromination of 1,1-dibenzyltetralin derivatives
摘要:
Addition of bromine to hydrocarbon 1 results in an aromatic alkylation to form the bicyclo[3.3.1]nonane derivative 5. Addition of bromine to ketone 3 in acetonitrile solution results in a dienone-phenol rearrangement to form phenol 6, while reaction of ketone 4 with phosphorus pentabromide yields phenols 10 and 11. This reaction results from a novel ''bromo ketone-phenol'' rearrangement, as demonstrated by the fact that bromo ketones 12 and 13 spontaneously isomerize to 10 and 11.
Reaction of ketone with phosphoruspentabromide or bromine results in bromination (or dibromination) at C-4. The resulting α-bromoketones rearrange rapidly in acid solutions to yield phenols and .